The present invention relates to a post-processing apparatus and a bookbinding apparatus having a sheet bundle storing device to accumulate sheets and to store sheet bundles, and related to an image forming system having the aforesaid post-processing apparatus and the bookbinding apparatus.
For example, in an electrophotographic method image forming apparatus has a high-speed performance, a multifunction and a network function, and its application as a printing apparatus is being expanding by connecting with a large capacity sheet feeding apparatus and a large capacity stacker.
In case the image forming apparatus is used as a printing apparatus, one system can perform a job from printing to bookbinding in a single successive workflow by connecting the bookbinding apparatus to bind printed matters.
In a bookbinding apparatus of Patent document 1, sheets on which images are formed in an image forming apparatus are accumulated in a sheet accumulating apparatus having an oblique sheet accumulating surface and forms a sheet bundle which composes a book, and the sheet bundle is transferred to jointing process section, and thereafter the sheet bundle is turned to a vertical condition, then glue is applied and a front cover is jointed onto the sheet bundle in the vertical condition, so as to make a book.
Also, a bookbinding process wherein one sheet bundle accumulating printed sheets is covered by a front cover sheet (coversheet) in U-shape is known as a bookbinding process.
In Patent document 1, a compact size bookbinding apparatus is proposed to enable coupling up of the image forming apparatus and the printing apparatus.
Patent Document 1: Unexamined Japanese Patent Application Publication No. 2004-209869
In the bookbinding apparatus disclosed by Patent document 1, when bookbinding is manually executed by changing into offline system, the sheet bundle is loaded on a coversheet supplying device. The sheet loaded is fed to a sheet bundle storing device one by one and a sheet bundle is formed by a sheet bundle conveyance device, and then bookbinding process is carried out in a bookbinding processing section having a glue applying device, a coversheet adhesion device and coversheet folding device.
However, in case of cast work, for example, up to a maximum of 300 pieces of the sheets are bound. Thus it takes an enormous time, if the sheets are fed one by one.